1. Field of the Invention
The present invention relates to a booster circuit having a new configuration, and more particularly, the invention relates to a semiconductor device using a charge pump as a booster circuit. Also, the invention relates to an electronic apparatus having the semiconductor device.
2. Description of the Related Art
The booster circuit is classified into the one with a coil and the one with a capacitor element. The latter one with a capacitor element is generally called a charge pump. A conventional charge pimp comprises: a first boosting block including a booster circuit for generating a voltage higher than an external power supply voltage, a diode that is connected to an output of the booster circuit, maintains the output voltage of the booster circuit at a predetermined level, and has a zener voltage higher than the external power supply voltage, and a voltage dividing resistor element for generating a reference voltage of a predetermined level in accordance with the voltage maintained at a predetermined level by the diode; and a second boosting block that generates and outputs a voltage of which the output level is controlled to be a predetermined level in accordance with the reference voltage generated by the first boosting block, has a higher output current capacity than the first boosting block, and does not operate in a standby mode (see Patent Document 1).    [Patent Document 1] Japanese Patent Laid-Open No. 7-79561
In the circuit disclosed in Patent Document 1, which requires a booster circuit for generating a voltage higher than an external power supply voltage, low power consumption is difficult to be achieved.
In addition, a display device incorporating the aforementioned conventional switching element for charge pump has the following problem. The charge pump, unlike other switching regulators, generally does not have a function to feed back an output voltage to stabilize the output, leading to a heavier current load and an unstable power supply with a higher output current.